This invention relates generally to lighting systems and is particularly directed to an improved strip lighting arrangement.
Strip lighting systems generally include a number of lamps, or light bulbs, aligned in an elongated array and connected in circuit to a common controller/power supply. Strip lighting systems have various commercial applications such as in advertisements, marquees, signs, etc., and are commonly used in noncommercial environments such as for decorative illumination as well as in functional applications such as in lighting stairways or other areas where only limited illumination is desired. These lighting systems generally operate at low voltages and currents, e.g., 24 VAC and 10 amps, with the controller frequently operated in a timed manner to sequentially and repetitively energize each lamp so as to provide a light "chasing" effect. The most common light "chasing" arrangement makes use of four separate circuits with each circuit coupled to every fourth lamp to simultaneously illuminate all lamps coupled to a first circuit for a first short time interval, followed by illumination of all lamps coupled to a second circuit for a second short time interval, etc. Such lighting arrangements and sequential illumination patterns are well known. However, prior art strip lighting systems have suffered from various limitations which have somewhat limited their general acceptance.
Referring to FIG. 1, there is shown a partially cutaway, exploded perspective view of a prior art strip lighting system 10. The strip lighting system 10 includes an elongated, linear housing 12 generally comprised of first and second lateral panels 14a, 14b and a bottom panel 14c. The first and second lateral panels 14a, 14b are coupled to the bottom panel 14c so as to provide an upper portion of the housing 12 with a slot-like aperture extending the length of the housing. An upper, inner portion of the housing 12 is provided with a first, upper pair of facing slots 18a, 18b in the first and second panels 14a, 14b, respectively. Similarly, an inner, lower portion of the housing is provided with a second, lower pair of facing slots 16a, 16b in the first and second lateral panels 14a, 14b, respectively. The second, lower pair of facing slots 16a, 16b is adapted to receive and engage an elongated, flat printed circuit board 20 whereon are positioned first and second conductive strips 22a and 22b. Positioned along the length of the circuit board 20 in spaced relation are a plurality of apertures within each of which is positioned a respective lamp 24. Each lamp is provided with a pair of conductive leads 25a, 25b which are respectively coupled in a conventional manner such as by soldering to first and second conductive strips 22a, 22b. In this manner, each lamp 24 is mounted to and coupled in circuit with the circuit board 20.
An AC voltage is applied across the first and second conductive strips 22a, 22b as well as across the various lamps 24 electrically coupled thereto for illuminating each of the lamps. An inverted four-sided, generally pyramidal-shaped reflector 26 having an aperture in the apex thereof is positioned over each of the lamps 24 such that a lamp is positioned within and extends through the aperture therein. The upper surface of each of the reflectors 26 is typically provided with a highly reflective coating. The second, upper pair of facing slots 16a, 16b is adapted to receive in sliding engagement respective edges of a generally flat light transmitting cover 28. The light transmitting cover may be either transparent or translucent depending upon the desired appearance of the strip lighting system and the application in which it is used.
The prior art strip lighting system of FIG. 1 suffers from various limitations. For example, by soldering each lamp to the conductors on the circuit board, replacement of the lamps following burn-out is difficult at best and is frequently impossible for the lamp user to perform. The soldered connection of the lamp leads also increases manufacturing time and cost and introduces the possibility of human error in the fabrication of the lighting circuit. Imprecise placement and soldering of a lamp on the circuit board may result in a shorting out of the lamp when power is applied to the strip lighting system. In addition, the sliding engagement of the light transmitting cover 28 as well as the circuit board 20 with the housing 12 precludes access to the lamps and removal of the circuit board from the housing where there is limited space at each end of the housing. Finally, the individual reflectors positioned immediately adjacent to each of the lamps provide only limited, discontinuous reflected illumination and, since the reflectors are not securely coupled to another structure in the lighting system, prevent usage of the lighting system in any lamp orientation other than generally vertical. Moreover, when the light transmitting cover 28 is removed from the housing 12, the individual reflectors 28 may be easily dislodged and become separated from the strip lighting assembly. The discontinuous nature of the reflector arrangement also exposes the underlying circuit board reducing the aesthetic appeal of this configuration.
The present invention is intended to overcome the aforementioned limitations of the prior art by providing an improved strip lighting arrangement which is easily, reliably and inexpensively fabricated and permits easy lamp replacement and electrical circuit maintenance in a sealed, attractive, high illumination and structurally strong and durable configuration.